The present invention relates to an electrical melting fuse for direct current circuits. This type of fuse has a response characteristic which depends on the flow direction of the electrical current. Fuses having such a current direction response characteristic are, for example, needed in the power supply network of vehicles, vessels, and/or aircraft. Such fuses are capable of providing a selective safety circuit breaker for the individual circuits in a direct current power supply network.
It is known to employ for the above purpose circuit breakers which are sensitive to a reverse current flow. It is also known to use parallel circuit paths provided with melting fuses responsive to different loads and arranged to cooperate with blocking diodes, the forward flow direction of which is opposite to the current flow direction in the respective circuit path. Circuit breakers of this type have relatively involved structural features as compared to simple melting fuses. However, simple melting fuse have the disadvantage when used for the mentioned purpose, that a relatively high and frequently not tolerable voltage drop occurs across the blocking diodes connected for cooperation with such melting fuses.